/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */

/*
  Part of the Processing project - http://processing.org

  Copyright (c) 2013-16 The Processing Foundation

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation, version 2.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty
  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA
*/

package processing.data;

import java.util.Arrays;
import java.util.Iterator;
import java.util.Random;

import processing.core.PApplet;

/**
 * Helper class for a list of Strings. Lists are designed to have some of the
 * features of ArrayLists, but to maintain the simplicity and efficiency of
 * working with arrays.
 *
 * Functions like sort() and shuffle() always act on the list itself. To get
 * a sorted copy, use list.copy().sort().
 *
 * @webref data:composite
 * @see IntList
 * @see FloatList
 */
public class StringList implements Iterable<String> {
  int count;
  String[] data;


  public StringList() {
    this(10);
  }

  /**
   * @nowebref
   */
  public StringList(int length) {
    data = new String[length];
  }

  /**
   * @nowebref
   */
  public StringList(String[] list) {
    count = list.length;
    data = new String[count];
    System.arraycopy(list, 0, data, 0, count);
  }


  /**
   * Construct a StringList from a random pile of objects. Null values will
   * stay null, but all the others will be converted to String values.
   */
  public StringList(Object... items) {
    count = items.length;
    data = new String[count];
    int index = 0;
    for (Object o : items) {
//      // Not gonna go with null values staying that way because perhaps
//      // the most common case here is to immediately call join() or similar.
//      data[index++] = String.valueOf(o);
      // Keep null values null (because join() will make non-null anyway)
      if (o != null) {  // leave null values null
        data[index] = o.toString();
      }
      index++;
    }
  }


  /**
   * Create from something iterable, for instance:
   * StringList list = new StringList(hashMap.keySet());
   *
   * @nowebref
   */
  public StringList(Iterable<String> iter) {
    this(10);
    for (String s : iter) {
      append(s);
    }
  }


  /**
   * Improve efficiency by removing allocated but unused entries from the
   * internal array used to store the data. Set to private, though it could
   * be useful to have this public if lists are frequently making drastic
   * size changes (from very large to very small).
   */
  private void crop() {
    if (count != data.length) {
      data = PApplet.subset(data, 0, count);
    }
  }


  /**
   * Get the length of the list.
   *
   * @webref stringlist:method
   * @brief Get the length of the list
   */
  public int size() {
    return count;
  }


  public void resize(int length) {
    if (length > data.length) {
      String[] temp = new String[length];
      System.arraycopy(data, 0, temp, 0, count);
      data = temp;

    } else if (length > count) {
      Arrays.fill(data, count, length, 0);
    }
    count = length;
  }


  /**
   * Remove all entries from the list.
   *
   * @webref stringlist:method
   * @brief Remove all entries from the list
   */
  public void clear() {
    count = 0;
  }


  /**
   * Get an entry at a particular index.
   *
   * @webref stringlist:method
   * @brief Get an entry at a particular index
   */
  public String get(int index) {
    if (index >= count) {
      throw new ArrayIndexOutOfBoundsException(index);
    }
    return data[index];
  }


  /**
   * Set the entry at a particular index. If the index is past the length of
   * the list, it'll expand the list to accommodate, and fill the intermediate
   * entries with 0s.
   *
   * @webref stringlist:method
   * @brief Set an entry at a particular index
   */
  public void set(int index, String what) {
    if (index >= count) {
      data = PApplet.expand(data, index+1);
      for (int i = count; i < index; i++) {
        data[i] = null;
      }
      count = index+1;
    }
    data[index] = what;
  }


  /** Just an alias for append(), but matches pop() */
  public void push(String value) {
    append(value);
  }


  public String pop() {
    if (count == 0) {
      throw new RuntimeException("Can't call pop() on an empty list");
    }
    String value = get(count-1);
    data[--count] = null;  // avoid leak
    return value;
  }


  /**
   * Remove an element from the specified index.
   *
   * @webref stringlist:method
   * @brief Remove an element from the specified index
   */
  public String remove(int index) {
    if (index < 0 || index >= count) {
      throw new ArrayIndexOutOfBoundsException(index);
    }
    String entry = data[index];
//    int[] outgoing = new int[count - 1];
//    System.arraycopy(data, 0, outgoing, 0, index);
//    count--;
//    System.arraycopy(data, index + 1, outgoing, 0, count - index);
//    data = outgoing;
    for (int i = index; i < count-1; i++) {
      data[i] = data[i+1];
    }
    count--;
    return entry;
  }


  // Remove the first instance of a particular value and return its index.
  public int removeValue(String value) {
    if (value == null) {
      for (int i = 0; i < count; i++) {
        if (data[i] == null) {
          remove(i);
          return i;
        }
      }
    } else {
      int index = index(value);
      if (index != -1) {
        remove(index);
        return index;
      }
    }
    return -1;
  }


  // Remove all instances of a particular value and return the count removed.
  public int removeValues(String value) {
    int ii = 0;
    if (value == null) {
      for (int i = 0; i < count; i++) {
        if (data[i] != null) {
          data[ii++] = data[i];
        }
      }
    } else {
      for (int i = 0; i < count; i++) {
        if (!value.equals(data[i])) {
          data[ii++] = data[i];
        }
      }
    }
    int removed = count - ii;
    count = ii;
    return removed;
  }


  // replace the first value that matches, return the index that was replaced
  public int replaceValue(String value, String newValue) {
    if (value == null) {
      for (int i = 0; i < count; i++) {
        if (data[i] == null) {
          data[i] = newValue;
          return i;
        }
      }
    } else {
      for (int i = 0; i < count; i++) {
        if (value.equals(data[i])) {
          data[i] = newValue;
          return i;
        }
      }
    }
    return -1;
  }


  // replace all values that match, return the count of those replaced
  public int replaceValues(String value, String newValue) {
    int changed = 0;
    if (value == null) {
      for (int i = 0; i < count; i++) {
        if (data[i] == null) {
          data[i] = newValue;
          changed++;
        }
      }
    } else {
      for (int i = 0; i < count; i++) {
        if (value.equals(data[i])) {
          data[i] = newValue;
          changed++;
        }
      }
    }
    return changed;
  }


  /**
   * Add a new entry to the list.
   *
   * @webref stringlist:method
   * @brief Add a new entry to the list
   */
  public void append(String value) {
    if (count == data.length) {
      data = PApplet.expand(data);
    }
    data[count++] = value;
  }


  public void append(String[] values) {
    for (String v : values) {
      append(v);
    }
  }


  public void append(StringList list) {
    for (String v : list.values()) {  // will concat the list...
      append(v);
    }
  }


  /** Add this value, but only if it's not already in the list. */
  public void appendUnique(String value) {
    if (!hasValue(value)) {
      append(value);
    }
  }


//  public void insert(int index, int value) {
//    if (index+1 > count) {
//      if (index+1 < data.length) {
//    }
//  }
//    if (index >= data.length) {
//      data = PApplet.expand(data, index+1);
//      data[index] = value;
//      count = index+1;
//
//    } else if (count == data.length) {
//    if (index >= count) {
//      //int[] temp = new int[count << 1];
//      System.arraycopy(data, 0, temp, 0, index);
//      temp[index] = value;
//      System.arraycopy(data, index, temp, index+1, count - index);
//      data = temp;
//
//    } else {
//      // data[] has room to grow
//      // for() loop believed to be faster than System.arraycopy over itself
//      for (int i = count; i > index; --i) {
//        data[i] = data[i-1];
//      }
//      data[index] = value;
//      count++;
//    }
//  }


  public void insert(int index, String value) {
    insert(index, new String[] { value });
  }


  // same as splice
  public void insert(int index, String[] values) {
    if (index < 0) {
      throw new IllegalArgumentException("insert() index cannot be negative: it was " + index);
    }
    if (index >= data.length) {
      throw new IllegalArgumentException("insert() index " + index + " is past the end of this list");
    }

    String[] temp = new String[count + values.length];

    // Copy the old values, but not more than already exist
    System.arraycopy(data, 0, temp, 0, Math.min(count, index));

    // Copy the new values into the proper place
    System.arraycopy(values, 0, temp, index, values.length);

//    if (index < count) {
    // The index was inside count, so it's a true splice/insert
    System.arraycopy(data, index, temp, index+values.length, count - index);
    count = count + values.length;
//    } else {
//      // The index was past 'count', so the new count is weirder
//      count = index + values.length;
//    }
    data = temp;
  }


  public void insert(int index, StringList list) {
    insert(index, list.values());
  }


    // below are aborted attempts at more optimized versions of the code
    // that are harder to read and debug...

//    if (index + values.length >= count) {
//      // We're past the current 'count', check to see if we're still allocated
//      // index 9, data.length = 10, values.length = 1
//      if (index + values.length < data.length) {
//        // There's still room for these entries, even though it's past 'count'.
//        // First clear out the entries leading up to it, however.
//        for (int i = count; i < index; i++) {
//          data[i] = 0;
//        }
//        data[index] =
//      }
//      if (index >= data.length) {
//        int length = index + values.length;
//        int[] temp = new int[length];
//        System.arraycopy(data, 0, temp, 0, count);
//        System.arraycopy(values, 0, temp, index, values.length);
//        data = temp;
//        count = data.length;
//      } else {
//
//      }
//
//    } else if (count == data.length) {
//      int[] temp = new int[count << 1];
//      System.arraycopy(data, 0, temp, 0, index);
//      temp[index] = value;
//      System.arraycopy(data, index, temp, index+1, count - index);
//      data = temp;
//
//    } else {
//      // data[] has room to grow
//      // for() loop believed to be faster than System.arraycopy over itself
//      for (int i = count; i > index; --i) {
//        data[i] = data[i-1];
//      }
//      data[index] = value;
//      count++;
//    }


  /** Return the first index of a particular value. */
  public int index(String what) {
    if (what == null) {
      for (int i = 0; i < count; i++) {
        if (data[i] == null) {
          return i;
        }
      }
    } else {
      for (int i = 0; i < count; i++) {
        if (what.equals(data[i])) {
          return i;
        }
      }
    }
    return -1;
  }


  // !!! TODO this is not yet correct, because it's not being reset when
  // the rest of the entries are changed
//  protected void cacheIndices() {
//    indexCache = new HashMap<Integer, Integer>();
//    for (int i = 0; i < count; i++) {
//      indexCache.put(data[i], i);
//    }
//  }

  /**
   * @webref stringlist:method
   * @brief Check if a value is a part of the list
   */
  public boolean hasValue(String value) {
    if (value == null) {
      for (int i = 0; i < count; i++) {
        if (data[i] == null) {
          return true;
        }
      }
    } else {
      for (int i = 0; i < count; i++) {
        if (value.equals(data[i])) {
          return true;
        }
      }
    }
    return false;
  }


  /**
   * Sorts the array in place.
   *
   * @webref stringlist:method
   * @brief Sorts the array in place
   */
  public void sort() {
    sortImpl(false);
  }


  /**
   * Reverse sort, orders values from highest to lowest.
   *
   * @webref stringlist:method
   * @brief Reverse sort, orders values from highest to lowest
   */
  public void sortReverse() {
    sortImpl(true);
  }


  private void sortImpl(final boolean reverse) {
    new Sort() {
      @Override
      public int size() {
        return count;
      }

      @Override
      public float compare(int a, int b) {
        float diff = data[a].compareToIgnoreCase(data[b]);
        return reverse ? -diff : diff;
      }

      @Override
      public void swap(int a, int b) {
        String temp = data[a];
        data[a] = data[b];
        data[b] = temp;
      }
    }.run();
  }


  // use insert()
//  public void splice(int index, int value) {
//  }


//  public void subset(int start) {
//    subset(start, count - start);
//  }
//
//
//  public void subset(int start, int num) {
//    for (int i = 0; i < num; i++) {
//      data[i] = data[i+start];
//    }
//    count = num;
//  }

  /**
   * @webref stringlist:method
   * @brief Reverse the order of the list elements
   */
  public void reverse() {
    int ii = count - 1;
    for (int i = 0; i < count/2; i++) {
      String t = data[i];
      data[i] = data[ii];
      data[ii] = t;
      --ii;
    }
  }


  /**
   * Randomize the order of the list elements. Note that this does not
   * obey the randomSeed() function in PApplet.
   *
   * @webref stringlist:method
   * @brief Randomize the order of the list elements
   */
  public void shuffle() {
    Random r = new Random();
    int num = count;
    while (num > 1) {
      int value = r.nextInt(num);
      num--;
      String temp = data[num];
      data[num] = data[value];
      data[value] = temp;
    }
  }


  /**
   * Randomize the list order using the random() function from the specified
   * sketch, allowing shuffle() to use its current randomSeed() setting.
   */
  public void shuffle(PApplet sketch) {
    int num = count;
    while (num > 1) {
      int value = (int) sketch.random(num);
      num--;
      String temp = data[num];
      data[num] = data[value];
      data[value] = temp;
    }
  }


  /**
   * Make the entire list lower case.
   *
   * @webref stringlist:method
   * @brief Make the entire list lower case
   */
  public void lower() {
    for (int i = 0; i < count; i++) {
      if (data[i] != null) {
        data[i] = data[i].toLowerCase();
      }
    }
  }


  /**
   * Make the entire list upper case.
   *
   * @webref stringlist:method
   * @brief Make the entire list upper case
   */
  public void upper() {
    for (int i = 0; i < count; i++) {
      if (data[i] != null) {
        data[i] = data[i].toUpperCase();
      }
    }
  }


  public StringList copy() {
    StringList outgoing = new StringList(data);
    outgoing.count = count;
    return outgoing;
  }


  /**
   * Returns the actual array being used to store the data. Suitable for
   * iterating with a for() loop, but modifying the list could cause terrible
   * things to happen.
   */
  public String[] values() {
    crop();
    return data;
  }


  @Override
  public Iterator<String> iterator() {
//    return valueIterator();
//  }
//
//
//  public Iterator<String> valueIterator() {
    return new Iterator<String>() {
      int index = -1;

      public void remove() {
        StringList.this.remove(index);
        index--;
      }

      public String next() {
        return data[++index];
      }

      public boolean hasNext() {
        return index+1 < count;
      }
    };
  }


  /**
   * Create a new array with a copy of all the values.
   *
   * @return an array sized by the length of the list with each of the values.
   * @webref stringlist:method
   * @brief Create a new array with a copy of all the values
   */
  public String[] array() {
    return array(null);
  }


  /**
   * Copy values into the specified array. If the specified array is null or
   * not the same size, a new array will be allocated.
   * @param array
   */
  public String[] array(String[] array) {
    if (array == null || array.length != count) {
      array = new String[count];
    }
    System.arraycopy(data, 0, array, 0, count);
    return array;
  }


  public StringList getSubset(int start) {
    return getSubset(start, count - start);
  }


  public StringList getSubset(int start, int num) {
    String[] subset = new String[num];
    System.arraycopy(data, start, subset, 0, num);
    return new StringList(subset);
  }


  /** Get a list of all unique entries. */
  public String[] getUnique() {
    return getTally().keyArray();
  }


  /** Count the number of times each String entry is found in this list. */
  public IntDict getTally() {
    IntDict outgoing = new IntDict();
    for (int i = 0; i < count; i++) {
      outgoing.increment(data[i]);
    }
    return outgoing;
  }


  /** Create a dictionary associating each entry in this list to its index. */
  public IntDict getOrder() {
    IntDict outgoing = new IntDict();
    for (int i = 0; i < count; i++) {
      outgoing.set(data[i], i);
    }
    return outgoing;
  }


  public String join(String separator) {
    if (count == 0) {
      return "";
    }
    StringBuilder sb = new StringBuilder();
    sb.append(data[0]);
    for (int i = 1; i < count; i++) {
      sb.append(separator);
      sb.append(data[i]);
    }
    return sb.toString();
  }


  public void print() {
    for (int i = 0; i < count; i++) {
      System.out.format("[%d] %s%n", i, data[i]);
    }
  }


  /**
   * Return this dictionary as a String in JSON format.
   */
  public String toJSON() {
    StringList temp = new StringList();
    for (String item : this) {
      temp.append(JSONObject.quote(item));
    }
    return "[ " + temp.join(", ") + " ]";
  }


  @Override
  public String toString() {
    return getClass().getSimpleName() + " size=" + size() + " " + toJSON();
  }
}
